1 //! This module implements [RFC 1946]: Intra-rustdoc-links
3 //! [RFC 1946]: https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md
5 use pulldown_cmark::LinkType;
6 use rustc_ast::util::comments::may_have_doc_links;
7 use rustc_data_structures::{
8 fx::{FxHashMap, FxHashSet},
11 use rustc_errors::{Applicability, Diagnostic};
12 use rustc_hir::def::Namespace::*;
13 use rustc_hir::def::{DefKind, Namespace, PerNS};
14 use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
15 use rustc_hir::Mutability;
16 use rustc_middle::ty::{DefIdTree, Ty, TyCtxt};
17 use rustc_middle::{bug, ty};
18 use rustc_resolve::ParentScope;
19 use rustc_session::lint::Lint;
20 use rustc_span::hygiene::MacroKind;
21 use rustc_span::symbol::{sym, Ident, Symbol};
22 use rustc_span::BytePos;
23 use smallvec::{smallvec, SmallVec};
29 use crate::clean::{self, utils::find_nearest_parent_module};
30 use crate::clean::{Crate, Item, ItemId, ItemLink, PrimitiveType};
31 use crate::core::DocContext;
32 use crate::html::markdown::{markdown_links, MarkdownLink};
33 use crate::lint::{BROKEN_INTRA_DOC_LINKS, PRIVATE_INTRA_DOC_LINKS};
34 use crate::passes::Pass;
35 use crate::visit::DocVisitor;
38 pub(crate) use early::early_resolve_intra_doc_links;
40 pub(crate) const COLLECT_INTRA_DOC_LINKS: Pass = Pass {
41 name: "collect-intra-doc-links",
42 run: collect_intra_doc_links,
43 description: "resolves intra-doc links",
46 fn collect_intra_doc_links(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
48 LinkCollector { cx, mod_ids: Vec::new(), visited_links: FxHashMap::default() };
49 collector.visit_crate(&krate);
53 #[derive(Copy, Clone, Debug, Hash)]
56 Primitive(PrimitiveType),
59 type ResolveRes = rustc_hir::def::Res<rustc_ast::NodeId>;
62 fn descr(self) -> &'static str {
64 Res::Def(kind, id) => ResolveRes::Def(kind, id).descr(),
65 Res::Primitive(_) => "builtin type",
69 fn article(self) -> &'static str {
71 Res::Def(kind, id) => ResolveRes::Def(kind, id).article(),
72 Res::Primitive(_) => "a",
76 fn name(self, tcx: TyCtxt<'_>) -> Symbol {
78 Res::Def(_, id) => tcx.item_name(id),
79 Res::Primitive(prim) => prim.as_sym(),
83 fn def_id(self, tcx: TyCtxt<'_>) -> DefId {
85 Res::Def(_, id) => id,
86 Res::Primitive(prim) => *PrimitiveType::primitive_locations(tcx).get(&prim).unwrap(),
90 fn from_def_id(tcx: TyCtxt<'_>, def_id: DefId) -> Res {
91 Res::Def(tcx.def_kind(def_id), def_id)
94 /// Used for error reporting.
95 fn disambiguator_suggestion(self) -> Suggestion {
96 let kind = match self {
97 Res::Primitive(_) => return Suggestion::Prefix("prim"),
98 Res::Def(kind, _) => kind,
100 if kind == DefKind::Macro(MacroKind::Bang) {
101 return Suggestion::Macro;
102 } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
103 return Suggestion::Function;
104 } else if kind == DefKind::Field {
105 return Suggestion::RemoveDisambiguator;
108 let prefix = match kind {
109 DefKind::Struct => "struct",
110 DefKind::Enum => "enum",
111 DefKind::Trait => "trait",
112 DefKind::Union => "union",
113 DefKind::Mod => "mod",
114 DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
117 DefKind::Static(_) => "static",
118 DefKind::Macro(MacroKind::Derive) => "derive",
119 // Now handle things that don't have a specific disambiguator
122 .expect("tried to calculate a disambiguator for a def without a namespace?")
124 Namespace::TypeNS => "type",
125 Namespace::ValueNS => "value",
126 Namespace::MacroNS => "macro",
130 Suggestion::Prefix(prefix)
134 impl TryFrom<ResolveRes> for Res {
137 fn try_from(res: ResolveRes) -> Result<Self, ()> {
138 use rustc_hir::def::Res::*;
140 Def(kind, id) => Ok(Res::Def(kind, id)),
141 PrimTy(prim) => Ok(Res::Primitive(PrimitiveType::from_hir(prim))),
143 NonMacroAttr(..) | Err => Result::Err(()),
144 other => bug!("unrecognized res {:?}", other),
149 /// The link failed to resolve. [`resolution_failure`] should look to see if there's
150 /// a more helpful error that can be given.
152 struct UnresolvedPath<'a> {
153 /// Item on which the link is resolved, used for resolving `Self`.
155 /// The scope the link was resolved in.
157 /// If part of the link resolved, this has the `Res`.
159 /// In `[std::io::Error::x]`, `std::io::Error` would be a partial resolution.
160 partial_res: Option<Res>,
161 /// The remaining unresolved path segments.
163 /// In `[std::io::Error::x]`, `x` would be unresolved.
164 unresolved: Cow<'a, str>,
168 enum ResolutionFailure<'a> {
169 /// This resolved, but with the wrong namespace.
171 /// What the link resolved to.
173 /// The expected namespace for the resolution, determined from the link's disambiguator.
175 /// E.g., for `[fn@Result]` this is [`Namespace::ValueNS`],
176 /// even though `Result`'s actual namespace is [`Namespace::TypeNS`].
177 expected_ns: Namespace,
179 NotResolved(UnresolvedPath<'a>),
182 #[derive(Clone, Copy, Debug)]
183 enum MalformedGenerics {
184 /// This link has unbalanced angle brackets.
186 /// For example, `Vec<T` should trigger this, as should `Vec<T>>`.
187 UnbalancedAngleBrackets,
188 /// The generics are not attached to a type.
190 /// For example, `<T>` should trigger this.
192 /// This is detected by checking if the path is empty after the generics are stripped.
194 /// The link uses fully-qualified syntax, which is currently unsupported.
196 /// For example, `<Vec as IntoIterator>::into_iter` should trigger this.
198 /// This is detected by checking if ` as ` (the keyword `as` with spaces around it) is inside
200 HasFullyQualifiedSyntax,
201 /// The link has an invalid path separator.
203 /// For example, `Vec:<T>:new()` should trigger this. Note that `Vec:new()` will **not**
204 /// trigger this because it has no generics and thus [`strip_generics_from_path`] will not be
207 /// Note that this will also **not** be triggered if the invalid path separator is inside angle
208 /// brackets because rustdoc mostly ignores what's inside angle brackets (except for
209 /// [`HasFullyQualifiedSyntax`](MalformedGenerics::HasFullyQualifiedSyntax)).
211 /// This is detected by checking if there is a colon followed by a non-colon in the link.
212 InvalidPathSeparator,
213 /// The link has too many angle brackets.
215 /// For example, `Vec<<T>>` should trigger this.
216 TooManyAngleBrackets,
217 /// The link has empty angle brackets.
219 /// For example, `Vec<>` should trigger this.
223 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
224 pub(crate) enum UrlFragment {
226 /// A part of a page that isn't a rust item.
228 /// Eg: `[Vector Examples](std::vec::Vec#examples)`
233 /// Render the fragment, including the leading `#`.
234 pub(crate) fn render(&self, s: &mut String, tcx: TyCtxt<'_>) {
237 &UrlFragment::Item(def_id) => {
238 let kind = match tcx.def_kind(def_id) {
239 DefKind::AssocFn => {
240 if tcx.impl_defaultness(def_id).has_value() {
246 DefKind::AssocConst => "associatedconstant.",
247 DefKind::AssocTy => "associatedtype.",
248 DefKind::Variant => "variant.",
250 let parent_id = tcx.parent(def_id);
251 if tcx.def_kind(parent_id) == DefKind::Variant {
252 s.push_str("variant.");
253 s.push_str(tcx.item_name(parent_id).as_str());
259 kind => bug!("unexpected associated item kind: {:?}", kind),
262 s.push_str(tcx.item_name(def_id).as_str());
264 UrlFragment::UserWritten(raw) => s.push_str(&raw),
269 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
270 struct ResolutionInfo {
273 dis: Option<Disambiguator>,
275 extra_fragment: Option<String>,
279 struct DiagnosticInfo<'a> {
283 link_range: Range<usize>,
286 struct LinkCollector<'a, 'tcx> {
287 cx: &'a mut DocContext<'tcx>,
288 /// A stack of modules used to decide what scope to resolve in.
290 /// The last module will be used if the parent scope of the current item is
293 /// Cache the resolved links so we can avoid resolving (and emitting errors for) the same link.
294 /// The link will be `None` if it could not be resolved (i.e. the error was cached).
295 visited_links: FxHashMap<ResolutionInfo, Option<(Res, Option<UrlFragment>)>>,
298 impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
299 /// Given a full link, parse it as an [enum struct variant].
301 /// In particular, this will return an error whenever there aren't three
302 /// full path segments left in the link.
304 /// [enum struct variant]: rustc_hir::VariantData::Struct
305 fn variant_field<'path>(
307 path_str: &'path str,
310 ) -> Result<(Res, DefId), UnresolvedPath<'path>> {
311 let tcx = self.cx.tcx;
312 let no_res = || UnresolvedPath {
316 unresolved: path_str.into(),
319 debug!("looking for enum variant {}", path_str);
320 let mut split = path_str.rsplitn(3, "::");
321 let variant_field_name = split
323 .map(|f| Symbol::intern(f))
324 .expect("fold_item should ensure link is non-empty");
326 // we're not sure this is a variant at all, so use the full string
327 // If there's no second component, the link looks like `[path]`.
328 // So there's no partial res and we should say the whole link failed to resolve.
329 split.next().map(|f| Symbol::intern(f)).ok_or_else(no_res)?;
332 .map(|f| f.to_owned())
333 // If there's no third component, we saw `[a::b]` before and it failed to resolve.
334 // So there's no partial res.
335 .ok_or_else(no_res)?;
336 let ty_res = self.resolve_path(&path, TypeNS, item_id, module_id).ok_or_else(no_res)?;
339 Res::Def(DefKind::Enum, did) => match tcx.type_of(did).kind() {
340 ty::Adt(def, _) if def.is_enum() => {
341 if let Some(field) = def.all_fields().find(|f| f.name == variant_field_name) {
342 Ok((ty_res, field.did))
347 partial_res: Some(Res::Def(DefKind::Enum, def.did())),
348 unresolved: variant_field_name.to_string().into(),
354 _ => Err(UnresolvedPath {
357 partial_res: Some(ty_res),
358 unresolved: variant_name.to_string().into(),
363 /// Given a primitive type, try to resolve an associated item.
364 fn resolve_primitive_associated_item(
366 prim_ty: PrimitiveType,
369 ) -> Option<(Res, DefId)> {
370 let tcx = self.cx.tcx;
372 prim_ty.impls(tcx).find_map(|impl_| {
373 tcx.associated_items(impl_)
374 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, impl_)
375 .map(|item| (Res::Primitive(prim_ty), item.def_id))
379 fn resolve_self_ty(&self, path_str: &str, ns: Namespace, item_id: ItemId) -> Option<Res> {
380 if ns != TypeNS || path_str != "Self" {
384 let tcx = self.cx.tcx;
387 .map(|def_id| match tcx.def_kind(def_id) {
388 def_kind @ (DefKind::AssocFn
389 | DefKind::AssocConst
392 | DefKind::Field) => {
393 let parent_def_id = tcx.parent(def_id);
394 if def_kind == DefKind::Field && tcx.def_kind(parent_def_id) == DefKind::Variant
396 tcx.parent(parent_def_id)
403 .and_then(|self_id| match tcx.def_kind(self_id) {
404 DefKind::Impl => self.def_id_to_res(self_id),
405 def_kind => Some(Res::Def(def_kind, self_id)),
409 /// Convenience wrapper around `resolve_rustdoc_path`.
411 /// This also handles resolving `true` and `false` as booleans.
412 /// NOTE: `resolve_rustdoc_path` knows only about paths, not about types.
413 /// Associated items will never be resolved by this function.
421 if let res @ Some(..) = self.resolve_self_ty(path_str, ns, item_id) {
425 // Resolver doesn't know about true, false, and types that aren't paths (e.g. `()`).
429 .doc_link_resolutions
430 .get(&(Symbol::intern(path_str), ns, module_id))
433 self.cx.enter_resolver(|resolver| {
435 ParentScope::module(resolver.expect_module(module_id), resolver);
436 resolver.resolve_rustdoc_path(path_str, ns, parent_scope)
439 .and_then(|res| res.try_into().ok())
440 .or_else(|| resolve_primitive(path_str, ns));
441 debug!("{} resolved to {:?} in namespace {:?}", path_str, result, ns);
445 /// Resolves a string as a path within a particular namespace. Returns an
446 /// optional URL fragment in the case of variants and methods.
449 path_str: &'path str,
453 ) -> Result<(Res, Option<DefId>), UnresolvedPath<'path>> {
454 if let Some(res) = self.resolve_path(path_str, ns, item_id, module_id) {
455 return Ok(match res {
457 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Variant,
459 ) => (Res::from_def_id(self.cx.tcx, self.cx.tcx.parent(def_id)), Some(def_id)),
462 } else if ns == MacroNS {
463 return Err(UnresolvedPath {
467 unresolved: path_str.into(),
471 // Try looking for methods and associated items.
472 let mut split = path_str.rsplitn(2, "::");
473 // NB: `split`'s first element is always defined, even if the delimiter was not present.
474 // NB: `item_str` could be empty when resolving in the root namespace (e.g. `::std`).
475 let item_str = split.next().unwrap();
476 let item_name = Symbol::intern(item_str);
477 let path_root = split
479 .map(|f| f.to_owned())
480 // If there's no `::`, it's not an associated item.
481 // So we can be sure that `rustc_resolve` was accurate when it said it wasn't resolved.
483 debug!("found no `::`, assuming {} was correctly not in scope", item_name);
488 unresolved: item_str.into(),
492 // FIXME(#83862): this arbitrarily gives precedence to primitives over modules to support
493 // links to primitives when `#[doc(primitive)]` is present. It should give an ambiguity
494 // error instead and special case *only* modules with `#[doc(primitive)]`, not all
496 resolve_primitive(&path_root, TypeNS)
497 .or_else(|| self.resolve_path(&path_root, TypeNS, item_id, module_id))
499 self.resolve_associated_item(ty_res, item_name, ns, module_id).map(Ok)
502 if ns == Namespace::ValueNS {
503 self.variant_field(path_str, item_id, module_id)
509 unresolved: path_root.into(),
513 .map(|(res, def_id)| (res, Some(def_id)))
516 /// Convert a DefId to a Res, where possible.
518 /// This is used for resolving type aliases.
519 fn def_id_to_res(&self, ty_id: DefId) -> Option<Res> {
520 use PrimitiveType::*;
521 Some(match *self.cx.tcx.type_of(ty_id).kind() {
522 ty::Bool => Res::Primitive(Bool),
523 ty::Char => Res::Primitive(Char),
524 ty::Int(ity) => Res::Primitive(ity.into()),
525 ty::Uint(uty) => Res::Primitive(uty.into()),
526 ty::Float(fty) => Res::Primitive(fty.into()),
527 ty::Str => Res::Primitive(Str),
528 ty::Tuple(tys) if tys.is_empty() => Res::Primitive(Unit),
529 ty::Tuple(_) => Res::Primitive(Tuple),
530 ty::Array(..) => Res::Primitive(Array),
531 ty::Slice(_) => Res::Primitive(Slice),
532 ty::RawPtr(_) => Res::Primitive(RawPointer),
533 ty::Ref(..) => Res::Primitive(Reference),
534 ty::FnDef(..) => panic!("type alias to a function definition"),
535 ty::FnPtr(_) => Res::Primitive(Fn),
536 ty::Never => Res::Primitive(Never),
537 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did, .. }, _)), _) | ty::Foreign(did) => {
538 Res::from_def_id(self.cx.tcx, did)
543 | ty::GeneratorWitness(_)
550 | ty::Error(_) => return None,
554 /// Convert a PrimitiveType to a Ty, where possible.
556 /// This is used for resolving trait impls for primitives
557 fn primitive_type_to_ty(&mut self, prim: PrimitiveType) -> Option<Ty<'tcx>> {
558 use PrimitiveType::*;
559 let tcx = self.cx.tcx;
561 // FIXME: Only simple types are supported here, see if we can support
562 // other types such as Tuple, Array, Slice, etc.
563 // See https://github.com/rust-lang/rust/issues/90703#issuecomment-1004263455
564 Some(tcx.mk_ty(match prim {
569 I8 => ty::Int(ty::IntTy::I8),
570 I16 => ty::Int(ty::IntTy::I16),
571 I32 => ty::Int(ty::IntTy::I32),
572 I64 => ty::Int(ty::IntTy::I64),
573 I128 => ty::Int(ty::IntTy::I128),
574 Isize => ty::Int(ty::IntTy::Isize),
575 F32 => ty::Float(ty::FloatTy::F32),
576 F64 => ty::Float(ty::FloatTy::F64),
577 U8 => ty::Uint(ty::UintTy::U8),
578 U16 => ty::Uint(ty::UintTy::U16),
579 U32 => ty::Uint(ty::UintTy::U32),
580 U64 => ty::Uint(ty::UintTy::U64),
581 U128 => ty::Uint(ty::UintTy::U128),
582 Usize => ty::Uint(ty::UintTy::Usize),
587 /// Resolve an associated item, returning its containing page's `Res`
588 /// and the fragment targeting the associated item on its page.
589 fn resolve_associated_item(
595 ) -> Option<(Res, DefId)> {
596 let tcx = self.cx.tcx;
599 Res::Primitive(prim) => {
600 self.resolve_primitive_associated_item(prim, ns, item_name).or_else(|| {
601 self.primitive_type_to_ty(prim)
603 resolve_associated_trait_item(ty, module_id, item_name, ns, self.cx)
605 .map(|item| (root_res, item.def_id))
608 Res::Def(DefKind::TyAlias, did) => {
609 // Resolve the link on the type the alias points to.
610 // FIXME: if the associated item is defined directly on the type alias,
611 // it will show up on its documentation page, we should link there instead.
612 let res = self.def_id_to_res(did)?;
613 self.resolve_associated_item(res, item_name, ns, module_id)
616 def_kind @ (DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::ForeignTy),
619 debug!("looking for associated item named {} for item {:?}", item_name, did);
620 // Checks if item_name is a variant of the `SomeItem` enum
621 if ns == TypeNS && def_kind == DefKind::Enum {
622 match tcx.type_of(did).kind() {
623 ty::Adt(adt_def, _) => {
624 for variant in adt_def.variants() {
625 if variant.name == item_name {
626 return Some((root_res, variant.def_id));
634 // Checks if item_name belongs to `impl SomeItem`
639 tcx.associated_items(imp).find_by_name_and_namespace(
641 Ident::with_dummy_span(item_name),
647 // There should only ever be one associated item that matches from any inherent impl
649 // Check if item_name belongs to `impl SomeTrait for SomeItem`
650 // FIXME(#74563): This gives precedence to `impl SomeItem`:
651 // Although having both would be ambiguous, use impl version for compatibility's sake.
652 // To handle that properly resolve() would have to support
653 // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
655 resolve_associated_trait_item(
664 debug!("got associated item {:?}", assoc_item);
666 if let Some(item) = assoc_item {
667 return Some((root_res, item.def_id));
670 if ns != Namespace::ValueNS {
673 debug!("looking for fields named {} for {:?}", item_name, did);
674 // FIXME: this doesn't really belong in `associated_item` (maybe `variant_field` is better?)
675 // NOTE: it's different from variant_field because it only resolves struct fields,
676 // not variant fields (2 path segments, not 3).
678 // We need to handle struct (and union) fields in this code because
679 // syntactically their paths are identical to associated item paths:
680 // `module::Type::field` and `module::Type::Assoc`.
682 // On the other hand, variant fields can't be mistaken for associated
683 // items because they look like this: `module::Type::Variant::field`.
685 // Variants themselves don't need to be handled here, even though
686 // they also look like associated items (`module::Type::Variant`),
687 // because they are real Rust syntax (unlike the intra-doc links
688 // field syntax) and are handled by the compiler's resolver.
689 let def = match tcx.type_of(did).kind() {
690 ty::Adt(def, _) if !def.is_enum() => def,
694 def.non_enum_variant().fields.iter().find(|item| item.name == item_name)?;
695 Some((root_res, field.did))
697 Res::Def(DefKind::Trait, did) => tcx
698 .associated_items(did)
699 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, did)
701 let res = Res::Def(item.kind.as_def_kind(), item.def_id);
709 fn full_res(tcx: TyCtxt<'_>, (base, assoc_item): (Res, Option<DefId>)) -> Res {
710 assoc_item.map_or(base, |def_id| Res::from_def_id(tcx, def_id))
713 /// Look to see if a resolved item has an associated item named `item_name`.
715 /// Given `[std::io::Error::source]`, where `source` is unresolved, this would
716 /// find `std::error::Error::source` and return
717 /// `<io::Error as error::Error>::source`.
718 fn resolve_associated_trait_item<'a>(
723 cx: &mut DocContext<'a>,
724 ) -> Option<ty::AssocItem> {
725 // FIXME: this should also consider blanket impls (`impl<T> X for T`). Unfortunately
726 // `get_auto_trait_and_blanket_impls` is broken because the caching behavior is wrong. In the
727 // meantime, just don't look for these blanket impls.
729 // Next consider explicit impls: `impl MyTrait for MyType`
730 // Give precedence to inherent impls.
731 let traits = trait_impls_for(cx, ty, module);
732 debug!("considering traits {:?}", traits);
733 let mut candidates = traits.iter().filter_map(|&(impl_, trait_)| {
735 .associated_items(trait_)
736 .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
738 trait_assoc_to_impl_assoc_item(cx.tcx, impl_, trait_assoc.def_id)
739 .unwrap_or(trait_assoc)
742 // FIXME(#74563): warn about ambiguity
743 debug!("the candidates were {:?}", candidates.clone().collect::<Vec<_>>());
744 candidates.next().copied()
747 /// Find the associated item in the impl `impl_id` that corresponds to the
748 /// trait associated item `trait_assoc_id`.
750 /// This function returns `None` if no associated item was found in the impl.
751 /// This can occur when the trait associated item has a default value that is
752 /// not overridden in the impl.
754 /// This is just a wrapper around [`TyCtxt::impl_item_implementor_ids()`] and
755 /// [`TyCtxt::associated_item()`] (with some helpful logging added).
756 #[instrument(level = "debug", skip(tcx), ret)]
757 fn trait_assoc_to_impl_assoc_item<'tcx>(
760 trait_assoc_id: DefId,
761 ) -> Option<&'tcx ty::AssocItem> {
762 let trait_to_impl_assoc_map = tcx.impl_item_implementor_ids(impl_id);
763 debug!(?trait_to_impl_assoc_map);
764 let impl_assoc_id = *trait_to_impl_assoc_map.get(&trait_assoc_id)?;
765 debug!(?impl_assoc_id);
766 Some(tcx.associated_item(impl_assoc_id))
769 /// Given a type, return all trait impls in scope in `module` for that type.
770 /// Returns a set of pairs of `(impl_id, trait_id)`.
772 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
773 /// So it is not stable to serialize cross-crate.
774 #[instrument(level = "debug", skip(cx))]
775 fn trait_impls_for<'a>(
776 cx: &mut DocContext<'a>,
779 ) -> FxHashSet<(DefId, DefId)> {
781 let iter = cx.resolver_caches.traits_in_scope[&module].iter().flat_map(|trait_candidate| {
782 let trait_ = trait_candidate.def_id;
783 trace!("considering explicit impl for trait {:?}", trait_);
785 // Look at each trait implementation to see if it's an impl for `did`
786 tcx.find_map_relevant_impl(trait_, ty, |impl_| {
787 let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
788 // Check if these are the same type.
789 let impl_type = trait_ref.self_ty();
791 "comparing type {} with kind {:?} against type {:?}",
796 // Fast path: if this is a primitive simple `==` will work
797 // NOTE: the `match` is necessary; see #92662.
798 // this allows us to ignore generics because the user input
799 // may not include the generic placeholders
800 // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
801 let saw_impl = impl_type == ty
802 || match (impl_type.kind(), ty.kind()) {
803 (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
804 debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did(), ty_def.did());
805 impl_def.did() == ty_def.did()
810 if saw_impl { Some((impl_, trait_)) } else { None }
816 /// Check for resolve collisions between a trait and its derive.
818 /// These are common and we should just resolve to the trait in that case.
819 fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_>>>) -> bool {
823 type_ns: Ok((Res::Def(DefKind::Trait, _), _)),
824 macro_ns: Ok((Res::Def(DefKind::Macro(MacroKind::Derive), _), _)),
830 impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
831 fn visit_item(&mut self, item: &Item) {
833 item.item_id.as_def_id().and_then(|did| find_nearest_parent_module(self.cx.tcx, did));
834 if parent_node.is_some() {
835 trace!("got parent node for {:?} {:?}, id {:?}", item.type_(), item.name, item.item_id);
838 let inner_docs = item.inner_docs(self.cx.tcx);
840 if item.is_mod() && inner_docs {
841 self.mod_ids.push(item.item_id.expect_def_id());
844 // We want to resolve in the lexical scope of the documentation.
845 // In the presence of re-exports, this is not the same as the module of the item.
846 // Rather than merging all documentation into one, resolve it one attribute at a time
847 // so we know which module it came from.
848 for (parent_module, doc) in item.attrs.prepare_to_doc_link_resolution() {
849 if !may_have_doc_links(&doc) {
852 debug!("combined_docs={}", doc);
853 // NOTE: if there are links that start in one crate and end in another, this will not resolve them.
854 // This is a degenerate case and it's not supported by rustdoc.
855 let parent_node = parent_module.or(parent_node);
856 let mut tmp_links = self
861 .expect("`markdown_links` are already borrowed");
862 if !tmp_links.contains_key(&doc) {
863 tmp_links.insert(doc.clone(), preprocessed_markdown_links(&doc));
865 for md_link in &tmp_links[&doc] {
866 let link = self.resolve_link(item, &doc, parent_node, md_link);
867 if let Some(link) = link {
868 self.cx.cache.intra_doc_links.entry(item.item_id).or_default().push(link);
871 self.cx.resolver_caches.markdown_links = Some(tmp_links);
876 self.mod_ids.push(item.item_id.expect_def_id());
879 self.visit_item_recur(item);
882 self.visit_item_recur(item)
887 enum PreprocessingError {
888 /// User error: `[std#x#y]` is not valid
890 Disambiguator(Range<usize>, String),
891 MalformedGenerics(MalformedGenerics, String),
894 impl PreprocessingError {
895 fn report(&self, cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
897 PreprocessingError::MultipleAnchors => report_multiple_anchors(cx, diag_info),
898 PreprocessingError::Disambiguator(range, msg) => {
899 disambiguator_error(cx, diag_info, range.clone(), msg)
901 PreprocessingError::MalformedGenerics(err, path_str) => {
902 report_malformed_generics(cx, diag_info, *err, path_str)
909 struct PreprocessingInfo {
911 disambiguator: Option<Disambiguator>,
912 extra_fragment: Option<String>,
916 // Not a typedef to avoid leaking several private structures from this module.
917 pub(crate) struct PreprocessedMarkdownLink(
918 Result<PreprocessingInfo, PreprocessingError>,
923 /// - `None` if the link should be ignored.
924 /// - `Some(Err)` if the link should emit an error
925 /// - `Some(Ok)` if the link is valid
927 /// `link_buffer` is needed for lifetime reasons; it will always be overwritten and the contents ignored.
929 ori_link: &MarkdownLink,
930 ) -> Option<Result<PreprocessingInfo, PreprocessingError>> {
931 // [] is mostly likely not supposed to be a link
932 if ori_link.link.is_empty() {
936 // Bail early for real links.
937 if ori_link.link.contains('/') {
941 let stripped = ori_link.link.replace('`', "");
942 let mut parts = stripped.split('#');
944 let link = parts.next().unwrap();
945 if link.trim().is_empty() {
946 // This is an anchor to an element of the current page, nothing to do in here!
949 let extra_fragment = parts.next();
950 if parts.next().is_some() {
951 // A valid link can't have multiple #'s
952 return Some(Err(PreprocessingError::MultipleAnchors));
955 // Parse and strip the disambiguator from the link, if present.
956 let (disambiguator, path_str, link_text) = match Disambiguator::from_str(link) {
957 Ok(Some((d, path, link_text))) => (Some(d), path.trim(), link_text.trim()),
958 Ok(None) => (None, link.trim(), link.trim()),
959 Err((err_msg, relative_range)) => {
960 // Only report error if we would not have ignored this link. See issue #83859.
961 if !should_ignore_link_with_disambiguators(link) {
962 let no_backticks_range = range_between_backticks(ori_link);
963 let disambiguator_range = (no_backticks_range.start + relative_range.start)
964 ..(no_backticks_range.start + relative_range.end);
965 return Some(Err(PreprocessingError::Disambiguator(disambiguator_range, err_msg)));
972 if should_ignore_link(path_str) {
976 // Strip generics from the path.
977 let path_str = if path_str.contains(['<', '>'].as_slice()) {
978 match strip_generics_from_path(path_str) {
981 debug!("link has malformed generics: {}", path_str);
982 return Some(Err(PreprocessingError::MalformedGenerics(err, path_str.to_owned())));
989 // Sanity check to make sure we don't have any angle brackets after stripping generics.
990 assert!(!path_str.contains(['<', '>'].as_slice()));
992 // The link is not an intra-doc link if it still contains spaces after stripping generics.
993 if path_str.contains(' ') {
997 Some(Ok(PreprocessingInfo {
1000 extra_fragment: extra_fragment.map(|frag| frag.to_owned()),
1001 link_text: link_text.to_owned(),
1005 fn preprocessed_markdown_links(s: &str) -> Vec<PreprocessedMarkdownLink> {
1006 markdown_links(s, |link| {
1007 preprocess_link(&link).map(|pp_link| PreprocessedMarkdownLink(pp_link, link))
1011 impl LinkCollector<'_, '_> {
1012 /// This is the entry point for resolving an intra-doc link.
1014 /// FIXME(jynelson): this is way too many arguments
1019 parent_node: Option<DefId>,
1020 link: &PreprocessedMarkdownLink,
1021 ) -> Option<ItemLink> {
1022 let PreprocessedMarkdownLink(pp_link, ori_link) = link;
1023 trace!("considering link '{}'", ori_link.link);
1025 let diag_info = DiagnosticInfo {
1028 ori_link: &ori_link.link,
1029 link_range: ori_link.range.clone(),
1032 let PreprocessingInfo { path_str, disambiguator, extra_fragment, link_text } =
1033 pp_link.as_ref().map_err(|err| err.report(self.cx, diag_info.clone())).ok()?;
1034 let disambiguator = *disambiguator;
1036 // In order to correctly resolve intra-doc links we need to
1037 // pick a base AST node to work from. If the documentation for
1038 // this module came from an inner comment (//!) then we anchor
1039 // our name resolution *inside* the module. If, on the other
1040 // hand it was an outer comment (///) then we anchor the name
1041 // resolution in the parent module on the basis that the names
1042 // used are more likely to be intended to be parent names. For
1043 // this, we set base_node to None for inner comments since
1044 // we've already pushed this node onto the resolution stack but
1045 // for outer comments we explicitly try and resolve against the
1046 // parent_node first.
1047 let inner_docs = item.inner_docs(self.cx.tcx);
1049 if item.is_mod() && inner_docs { self.mod_ids.last().copied() } else { parent_node };
1050 let module_id = base_node.expect("doc link without parent module");
1052 let (mut res, fragment) = self.resolve_with_disambiguator_cached(
1054 item_id: item.item_id,
1057 path_str: path_str.to_owned(),
1058 extra_fragment: extra_fragment.clone(),
1060 diag_info.clone(), // this struct should really be Copy, but Range is not :(
1061 // For reference-style links we want to report only one error so unsuccessful
1062 // resolutions are cached, for other links we want to report an error every
1063 // time so they are not cached.
1064 matches!(ori_link.kind, LinkType::Reference | LinkType::Shortcut),
1067 // Check for a primitive which might conflict with a module
1068 // Report the ambiguity and require that the user specify which one they meant.
1069 // FIXME: could there ever be a primitive not in the type namespace?
1072 None | Some(Disambiguator::Namespace(Namespace::TypeNS) | Disambiguator::Primitive)
1073 ) && !matches!(res, Res::Primitive(_))
1075 if let Some(prim) = resolve_primitive(path_str, TypeNS) {
1077 if matches!(disambiguator, Some(Disambiguator::Primitive)) {
1080 // `[char]` when a `char` module is in scope
1081 let candidates = vec![res, prim];
1082 ambiguity_error(self.cx, diag_info, path_str, candidates);
1089 Res::Primitive(prim) => {
1090 if let Some(UrlFragment::Item(id)) = fragment {
1091 // We're actually resolving an associated item of a primitive, so we need to
1092 // verify the disambiguator (if any) matches the type of the associated item.
1093 // This case should really follow the same flow as the `Res::Def` branch below,
1094 // but attempting to add a call to `clean::register_res` causes an ICE. @jyn514
1095 // thinks `register_res` is only needed for cross-crate re-exports, but Rust
1096 // doesn't allow statements like `use str::trim;`, making this a (hopefully)
1097 // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
1098 // for discussion on the matter.
1099 let kind = self.cx.tcx.def_kind(id);
1100 self.verify_disambiguator(
1110 // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
1111 // However I'm not sure how to check that across crates.
1112 if prim == PrimitiveType::RawPointer
1113 && item.item_id.is_local()
1114 && !self.cx.tcx.features().intra_doc_pointers
1116 self.report_rawptr_assoc_feature_gate(dox, ori_link, item);
1119 match disambiguator {
1120 Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
1122 self.report_disambiguator_mismatch(
1123 path_str, ori_link, other, res, &diag_info,
1131 link: ori_link.link.clone(),
1132 link_text: link_text.clone(),
1133 page_id: res.def_id(self.cx.tcx),
1137 Res::Def(kind, id) => {
1138 let (kind_for_dis, id_for_dis) = if let Some(UrlFragment::Item(id)) = fragment {
1139 (self.cx.tcx.def_kind(id), id)
1143 self.verify_disambiguator(
1153 let page_id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
1155 link: ori_link.link.clone(),
1156 link_text: link_text.clone(),
1164 fn verify_disambiguator(
1167 ori_link: &MarkdownLink,
1170 disambiguator: Option<Disambiguator>,
1172 diag_info: &DiagnosticInfo<'_>,
1174 debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
1176 // Disallow e.g. linking to enums with `struct@`
1177 debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
1178 match (kind, disambiguator) {
1179 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
1180 // NOTE: this allows 'method' to mean both normal functions and associated functions
1181 // This can't cause ambiguity because both are in the same namespace.
1182 | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
1183 // These are namespaces; allow anything in the namespace to match
1184 | (_, Some(Disambiguator::Namespace(_)))
1185 // If no disambiguator given, allow anything
1187 // All of these are valid, so do nothing
1189 (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
1190 (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
1191 self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
1196 // item can be non-local e.g. when using #[doc(primitive = "pointer")]
1197 if let Some((src_id, dst_id)) = id
1199 // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
1200 // would presumably panic if a fake `DefIndex` were passed.
1201 .and_then(|dst_id| {
1202 item.item_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
1205 if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
1206 && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
1208 privacy_error(self.cx, diag_info, path_str);
1215 fn report_disambiguator_mismatch(
1218 ori_link: &MarkdownLink,
1219 specified: Disambiguator,
1221 diag_info: &DiagnosticInfo<'_>,
1223 // The resolved item did not match the disambiguator; give a better error than 'not found'
1224 let msg = format!("incompatible link kind for `{}`", path_str);
1225 let callback = |diag: &mut Diagnostic, sp: Option<rustc_span::Span>| {
1227 "this link resolved to {} {}, which is not {} {}",
1230 specified.article(),
1233 if let Some(sp) = sp {
1234 diag.span_label(sp, ¬e);
1238 suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
1240 report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, diag_info, callback);
1243 fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
1245 super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
1246 .unwrap_or_else(|| item.attr_span(self.cx.tcx));
1247 rustc_session::parse::feature_err(
1248 &self.cx.tcx.sess.parse_sess,
1249 sym::intra_doc_pointers,
1251 "linking to associated items of raw pointers is experimental",
1253 .note("rustdoc does not allow disambiguating between `*const` and `*mut`, and pointers are unstable until it does")
1257 fn resolve_with_disambiguator_cached(
1259 key: ResolutionInfo,
1260 diag: DiagnosticInfo<'_>,
1261 // If errors are cached then they are only reported on first occurrence
1262 // which we want in some cases but not in others.
1264 ) -> Option<(Res, Option<UrlFragment>)> {
1265 if let Some(res) = self.visited_links.get(&key) {
1266 if res.is_some() || cache_errors {
1271 let res = self.resolve_with_disambiguator(&key, diag.clone()).and_then(|(res, def_id)| {
1272 let fragment = match (&key.extra_fragment, def_id) {
1273 (Some(_), Some(def_id)) => {
1274 report_anchor_conflict(self.cx, diag, def_id);
1277 (Some(u_frag), None) => Some(UrlFragment::UserWritten(u_frag.clone())),
1278 (None, Some(def_id)) => Some(UrlFragment::Item(def_id)),
1279 (None, None) => None,
1281 Some((res, fragment))
1284 if res.is_some() || cache_errors {
1285 self.visited_links.insert(key, res.clone());
1290 /// After parsing the disambiguator, resolve the main part of the link.
1291 // FIXME(jynelson): wow this is just so much
1292 fn resolve_with_disambiguator(
1294 key: &ResolutionInfo,
1295 diag: DiagnosticInfo<'_>,
1296 ) -> Option<(Res, Option<DefId>)> {
1297 let disambiguator = key.dis;
1298 let path_str = &key.path_str;
1299 let item_id = key.item_id;
1300 let base_node = key.module_id;
1302 match disambiguator.map(Disambiguator::ns) {
1303 Some(expected_ns) => {
1304 match self.resolve(path_str, expected_ns, item_id, base_node) {
1305 Ok(res) => Some(res),
1307 // We only looked in one namespace. Try to give a better error if possible.
1308 // FIXME: really it should be `resolution_failure` that does this, not `resolve_with_disambiguator`.
1309 // See https://github.com/rust-lang/rust/pull/76955#discussion_r493953382 for a good approach.
1310 let mut err = ResolutionFailure::NotResolved(err);
1311 for other_ns in [TypeNS, ValueNS, MacroNS] {
1312 if other_ns != expected_ns {
1314 self.resolve(path_str, other_ns, item_id, base_node)
1316 err = ResolutionFailure::WrongNamespace {
1317 res: full_res(self.cx.tcx, res),
1324 resolution_failure(self, diag, path_str, disambiguator, smallvec![err])
1330 let mut candidate = |ns| {
1331 self.resolve(path_str, ns, item_id, base_node)
1332 .map_err(ResolutionFailure::NotResolved)
1335 let candidates = PerNS {
1336 macro_ns: candidate(MacroNS),
1337 type_ns: candidate(TypeNS),
1338 value_ns: candidate(ValueNS).and_then(|(res, def_id)| {
1340 // Constructors are picked up in the type namespace.
1341 Res::Def(DefKind::Ctor(..), _) => {
1342 Err(ResolutionFailure::WrongNamespace { res, expected_ns: TypeNS })
1344 _ => Ok((res, def_id)),
1349 let len = candidates.iter().filter(|res| res.is_ok()).count();
1352 return resolution_failure(
1357 candidates.into_iter().filter_map(|res| res.err()).collect(),
1362 Some(candidates.into_iter().find_map(|res| res.ok()).unwrap())
1363 } else if len == 2 && is_derive_trait_collision(&candidates) {
1364 Some(candidates.type_ns.unwrap())
1366 let ignore_macro = is_derive_trait_collision(&candidates);
1367 // If we're reporting an ambiguity, don't mention the namespaces that failed
1368 let mut candidates =
1369 candidates.map(|candidate| candidate.ok().map(|(res, _)| res));
1371 candidates.macro_ns = None;
1373 ambiguity_error(self.cx, diag, path_str, candidates.present_items().collect());
1381 /// Get the section of a link between the backticks,
1382 /// or the whole link if there aren't any backticks.
1390 fn range_between_backticks(ori_link: &MarkdownLink) -> Range<usize> {
1391 let after_first_backtick_group = ori_link.link.bytes().position(|b| b != b'`').unwrap_or(0);
1392 let before_second_backtick_group = ori_link
1395 .skip(after_first_backtick_group)
1396 .position(|b| b == b'`')
1397 .unwrap_or(ori_link.link.len());
1398 (ori_link.range.start + after_first_backtick_group)
1399 ..(ori_link.range.start + before_second_backtick_group)
1402 /// Returns true if we should ignore `link` due to it being unlikely
1403 /// that it is an intra-doc link. `link` should still have disambiguators
1404 /// if there were any.
1406 /// The difference between this and [`should_ignore_link()`] is that this
1407 /// check should only be used on links that still have disambiguators.
1408 fn should_ignore_link_with_disambiguators(link: &str) -> bool {
1409 link.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;@()".contains(ch)))
1412 /// Returns true if we should ignore `path_str` due to it being unlikely
1413 /// that it is an intra-doc link.
1414 fn should_ignore_link(path_str: &str) -> bool {
1415 path_str.contains(|ch: char| !(ch.is_alphanumeric() || ":_<>, !*&;".contains(ch)))
1418 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1419 /// Disambiguators for a link.
1420 enum Disambiguator {
1423 /// This is buggy, see <https://github.com/rust-lang/rust/pull/77875#discussion_r503583103>
1425 /// `struct@` or `f()`
1428 Namespace(Namespace),
1431 impl Disambiguator {
1432 /// Given a link, parse and return `(disambiguator, path_str, link_text)`.
1434 /// This returns `Ok(Some(...))` if a disambiguator was found,
1435 /// `Ok(None)` if no disambiguator was found, or `Err(...)`
1436 /// if there was a problem with the disambiguator.
1437 fn from_str(link: &str) -> Result<Option<(Self, &str, &str)>, (String, Range<usize>)> {
1438 use Disambiguator::{Kind, Namespace as NS, Primitive};
1440 if let Some(idx) = link.find('@') {
1441 let (prefix, rest) = link.split_at(idx);
1442 let d = match prefix {
1443 "struct" => Kind(DefKind::Struct),
1444 "enum" => Kind(DefKind::Enum),
1445 "trait" => Kind(DefKind::Trait),
1446 "union" => Kind(DefKind::Union),
1447 "module" | "mod" => Kind(DefKind::Mod),
1448 "const" | "constant" => Kind(DefKind::Const),
1449 "static" => Kind(DefKind::Static(Mutability::Not)),
1450 "function" | "fn" | "method" => Kind(DefKind::Fn),
1451 "derive" => Kind(DefKind::Macro(MacroKind::Derive)),
1452 "type" => NS(Namespace::TypeNS),
1453 "value" => NS(Namespace::ValueNS),
1454 "macro" => NS(Namespace::MacroNS),
1455 "prim" | "primitive" => Primitive,
1456 _ => return Err((format!("unknown disambiguator `{}`", prefix), 0..idx)),
1458 Ok(Some((d, &rest[1..], &rest[1..])))
1461 ("!()", DefKind::Macro(MacroKind::Bang)),
1462 ("!{}", DefKind::Macro(MacroKind::Bang)),
1463 ("![]", DefKind::Macro(MacroKind::Bang)),
1464 ("()", DefKind::Fn),
1465 ("!", DefKind::Macro(MacroKind::Bang)),
1467 for (suffix, kind) in suffixes {
1468 if let Some(path_str) = link.strip_suffix(suffix) {
1469 // Avoid turning `!` or `()` into an empty string
1470 if !path_str.is_empty() {
1471 return Ok(Some((Kind(kind), path_str, link)));
1479 fn ns(self) -> Namespace {
1481 Self::Namespace(n) => n,
1483 k.ns().expect("only DefKinds with a valid namespace can be disambiguators")
1485 Self::Primitive => TypeNS,
1489 fn article(self) -> &'static str {
1491 Self::Namespace(_) => panic!("article() doesn't make sense for namespaces"),
1492 Self::Kind(k) => k.article(),
1493 Self::Primitive => "a",
1497 fn descr(self) -> &'static str {
1499 Self::Namespace(n) => n.descr(),
1500 // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
1501 // printing "module" vs "crate" so using the wrong ID is not a huge problem
1502 Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
1503 Self::Primitive => "builtin type",
1508 /// A suggestion to show in a diagnostic.
1511 Prefix(&'static str),
1516 /// `foo` without any disambiguator
1517 RemoveDisambiguator,
1521 fn descr(&self) -> Cow<'static, str> {
1523 Self::Prefix(x) => format!("prefix with `{}@`", x).into(),
1524 Self::Function => "add parentheses".into(),
1525 Self::Macro => "add an exclamation mark".into(),
1526 Self::RemoveDisambiguator => "remove the disambiguator".into(),
1530 fn as_help(&self, path_str: &str) -> String {
1531 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1533 Self::Prefix(prefix) => format!("{}@{}", prefix, path_str),
1534 Self::Function => format!("{}()", path_str),
1535 Self::Macro => format!("{}!", path_str),
1536 Self::RemoveDisambiguator => path_str.into(),
1544 sp: rustc_span::Span,
1545 ) -> Vec<(rustc_span::Span, String)> {
1546 let inner_sp = match ori_link.find('(') {
1547 Some(index) => sp.with_hi(sp.lo() + BytePos(index as _)),
1550 let inner_sp = match ori_link.find('!') {
1551 Some(index) => inner_sp.with_hi(inner_sp.lo() + BytePos(index as _)),
1554 let inner_sp = match ori_link.find('@') {
1555 Some(index) => inner_sp.with_lo(inner_sp.lo() + BytePos(index as u32 + 1)),
1559 Self::Prefix(prefix) => {
1560 // FIXME: if this is an implied shortcut link, it's bad style to suggest `@`
1561 let mut sugg = vec![(sp.with_hi(inner_sp.lo()), format!("{}@", prefix))];
1562 if sp.hi() != inner_sp.hi() {
1563 sugg.push((inner_sp.shrink_to_hi().with_hi(sp.hi()), String::new()));
1568 let mut sugg = vec![(inner_sp.shrink_to_hi().with_hi(sp.hi()), "()".to_string())];
1569 if sp.lo() != inner_sp.lo() {
1570 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1575 let mut sugg = vec![(inner_sp.shrink_to_hi(), "!".to_string())];
1576 if sp.lo() != inner_sp.lo() {
1577 sugg.push((inner_sp.shrink_to_lo().with_lo(sp.lo()), String::new()));
1581 Self::RemoveDisambiguator => vec![(sp, path_str.into())],
1586 /// Reports a diagnostic for an intra-doc link.
1588 /// If no link range is provided, or the source span of the link cannot be determined, the span of
1589 /// the entire documentation block is used for the lint. If a range is provided but the span
1590 /// calculation fails, a note is added to the diagnostic pointing to the link in the markdown.
1592 /// The `decorate` callback is invoked in all cases to allow further customization of the
1593 /// diagnostic before emission. If the span of the link was able to be determined, the second
1594 /// parameter of the callback will contain it, and the primary span of the diagnostic will be set
1596 fn report_diagnostic(
1598 lint: &'static Lint,
1600 DiagnosticInfo { item, ori_link: _, dox, link_range }: &DiagnosticInfo<'_>,
1601 decorate: impl FnOnce(&mut Diagnostic, Option<rustc_span::Span>),
1603 let Some(hir_id) = DocContext::as_local_hir_id(tcx, item.item_id)
1605 // If non-local, no need to check anything.
1606 info!("ignoring warning from parent crate: {}", msg);
1610 let sp = item.attr_span(tcx);
1612 tcx.struct_span_lint_hir(lint, hir_id, sp, msg, |lint| {
1614 super::source_span_for_markdown_range(tcx, dox, link_range, &item.attrs).map(|sp| {
1615 if dox.as_bytes().get(link_range.start) == Some(&b'`')
1616 && dox.as_bytes().get(link_range.end - 1) == Some(&b'`')
1618 sp.with_lo(sp.lo() + BytePos(1)).with_hi(sp.hi() - BytePos(1))
1624 if let Some(sp) = span {
1627 // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
1630 // last_new_line_offset
1631 let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
1632 let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
1634 // Print the line containing the `link_range` and manually mark it with '^'s.
1636 "the link appears in this line:\n\n{line}\n\
1637 {indicator: <before$}{indicator:^<found$}",
1640 before = link_range.start - last_new_line_offset,
1641 found = link_range.len(),
1645 decorate(lint, span);
1651 /// Reports a link that failed to resolve.
1653 /// This also tries to resolve any intermediate path segments that weren't
1654 /// handled earlier. For example, if passed `Item::Crate(std)` and `path_str`
1655 /// `std::io::Error::x`, this will resolve `std::io::Error`.
1656 fn resolution_failure(
1657 collector: &mut LinkCollector<'_, '_>,
1658 diag_info: DiagnosticInfo<'_>,
1660 disambiguator: Option<Disambiguator>,
1661 kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
1662 ) -> Option<(Res, Option<DefId>)> {
1663 let tcx = collector.cx.tcx;
1664 let mut recovered_res = None;
1667 BROKEN_INTRA_DOC_LINKS,
1668 &format!("unresolved link to `{}`", path_str),
1671 let item = |res: Res| format!("the {} `{}`", res.descr(), res.name(tcx),);
1672 let assoc_item_not_allowed = |res: Res| {
1673 let name = res.name(tcx);
1675 "`{}` is {} {}, not a module or type, and cannot have associated items",
1681 // ignore duplicates
1682 let mut variants_seen = SmallVec::<[_; 3]>::new();
1683 for mut failure in kinds {
1684 let variant = std::mem::discriminant(&failure);
1685 if variants_seen.contains(&variant) {
1688 variants_seen.push(variant);
1690 if let ResolutionFailure::NotResolved(UnresolvedPath {
1699 let item_id = *item_id;
1700 let module_id = *module_id;
1701 // FIXME(jynelson): this might conflict with my `Self` fix in #76467
1702 // FIXME: maybe use itertools `collect_tuple` instead?
1703 fn split(path: &str) -> Option<(&str, &str)> {
1704 let mut splitter = path.rsplitn(2, "::");
1705 splitter.next().and_then(|right| splitter.next().map(|left| (left, right)))
1708 // Check if _any_ parent of the path gets resolved.
1709 // If so, report it and say the first which failed; if not, say the first path segment didn't resolve.
1710 let mut name = path_str;
1712 let Some((start, end)) = split(name) else {
1713 // avoid bug that marked [Quux::Z] as missing Z, not Quux
1714 if partial_res.is_none() {
1715 *unresolved = name.into();
1720 for ns in [TypeNS, ValueNS, MacroNS] {
1721 if let Ok(res) = collector.resolve(start, ns, item_id, module_id) {
1722 debug!("found partial_res={:?}", res);
1723 *partial_res = Some(full_res(collector.cx.tcx, res));
1724 *unresolved = end.into();
1728 *unresolved = end.into();
1731 let last_found_module = match *partial_res {
1732 Some(Res::Def(DefKind::Mod, id)) => Some(id),
1733 None => Some(module_id),
1736 // See if this was a module: `[path]` or `[std::io::nope]`
1737 if let Some(module) = last_found_module {
1738 let note = if partial_res.is_some() {
1739 // Part of the link resolved; e.g. `std::io::nonexistent`
1740 let module_name = tcx.item_name(module);
1741 format!("no item named `{}` in module `{}`", unresolved, module_name)
1743 // None of the link resolved; e.g. `Notimported`
1744 format!("no item named `{}` in scope", unresolved)
1746 if let Some(span) = sp {
1747 diag.span_label(span, ¬e);
1752 if !path_str.contains("::") {
1753 if disambiguator.map_or(true, |d| d.ns() == MacroNS)
1754 && let Some(&res) = collector.cx.resolver_caches.all_macro_rules
1755 .get(&Symbol::intern(path_str))
1758 "`macro_rules` named `{path_str}` exists in this crate, \
1759 but it is not in scope at this link's location"
1761 recovered_res = res.try_into().ok().map(|res| (res, None));
1763 // If the link has `::` in it, assume it was meant to be an
1764 // intra-doc link. Otherwise, the `[]` might be unrelated.
1765 diag.help("to escape `[` and `]` characters, \
1766 add '\\' before them like `\\[` or `\\]`");
1773 // Otherwise, it must be an associated item or variant
1774 let res = partial_res.expect("None case was handled by `last_found_module`");
1775 let name = res.name(tcx);
1776 let kind = match res {
1777 Res::Def(kind, _) => Some(kind),
1778 Res::Primitive(_) => None,
1780 let path_description = if let Some(kind) = kind {
1782 Mod | ForeignMod => "inner item",
1783 Struct => "field or associated item",
1784 Enum | Union => "variant or associated item",
1802 let note = assoc_item_not_allowed(res);
1803 if let Some(span) = sp {
1804 diag.span_label(span, ¬e);
1810 Trait | TyAlias | ForeignTy | OpaqueTy | ImplTraitPlaceholder
1811 | TraitAlias | TyParam | Static(_) => "associated item",
1812 Impl | GlobalAsm => unreachable!("not a path"),
1818 "the {} `{}` has no {} named `{}`",
1821 disambiguator.map_or(path_description, |d| d.descr()),
1824 if let Some(span) = sp {
1825 diag.span_label(span, ¬e);
1832 let note = match failure {
1833 ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
1834 ResolutionFailure::WrongNamespace { res, expected_ns } => {
1835 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1838 "this link resolves to {}, which is not in the {} namespace",
1844 if let Some(span) = sp {
1845 diag.span_label(span, ¬e);
1856 fn report_multiple_anchors(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>) {
1857 let msg = format!("`{}` contains multiple anchors", diag_info.ori_link);
1858 anchor_failure(cx, diag_info, &msg, 1)
1861 fn report_anchor_conflict(cx: &DocContext<'_>, diag_info: DiagnosticInfo<'_>, def_id: DefId) {
1862 let (link, kind) = (diag_info.ori_link, Res::from_def_id(cx.tcx, def_id).descr());
1863 let msg = format!("`{link}` contains an anchor, but links to {kind}s are already anchored");
1864 anchor_failure(cx, diag_info, &msg, 0)
1867 /// Report an anchor failure.
1869 cx: &DocContext<'_>,
1870 diag_info: DiagnosticInfo<'_>,
1874 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, sp| {
1875 if let Some(mut sp) = sp {
1876 if let Some((fragment_offset, _)) =
1877 diag_info.ori_link.char_indices().filter(|(_, x)| *x == '#').nth(anchor_idx)
1879 sp = sp.with_lo(sp.lo() + BytePos(fragment_offset as _));
1881 diag.span_label(sp, "invalid anchor");
1886 /// Report an error in the link disambiguator.
1887 fn disambiguator_error(
1888 cx: &DocContext<'_>,
1889 mut diag_info: DiagnosticInfo<'_>,
1890 disambiguator_range: Range<usize>,
1893 diag_info.link_range = disambiguator_range;
1894 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, msg, &diag_info, |diag, _sp| {
1896 "see {}/rustdoc/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators",
1897 crate::DOC_RUST_LANG_ORG_CHANNEL
1903 fn report_malformed_generics(
1904 cx: &DocContext<'_>,
1905 diag_info: DiagnosticInfo<'_>,
1906 err: MalformedGenerics,
1911 BROKEN_INTRA_DOC_LINKS,
1912 &format!("unresolved link to `{}`", path_str),
1915 let note = match err {
1916 MalformedGenerics::UnbalancedAngleBrackets => "unbalanced angle brackets",
1917 MalformedGenerics::MissingType => "missing type for generic parameters",
1918 MalformedGenerics::HasFullyQualifiedSyntax => {
1920 "see https://github.com/rust-lang/rust/issues/74563 for more information",
1922 "fully-qualified syntax is unsupported"
1924 MalformedGenerics::InvalidPathSeparator => "has invalid path separator",
1925 MalformedGenerics::TooManyAngleBrackets => "too many angle brackets",
1926 MalformedGenerics::EmptyAngleBrackets => "empty angle brackets",
1928 if let Some(span) = sp {
1929 diag.span_label(span, note);
1937 /// Report an ambiguity error, where there were multiple possible resolutions.
1939 cx: &DocContext<'_>,
1940 diag_info: DiagnosticInfo<'_>,
1942 candidates: Vec<Res>,
1944 let mut msg = format!("`{}` is ", path_str);
1946 match candidates.as_slice() {
1947 [first_def, second_def] => {
1949 "both {} {} and {} {}",
1950 first_def.article(),
1952 second_def.article(),
1957 let mut candidates = candidates.iter().peekable();
1958 while let Some(res) = candidates.next() {
1959 if candidates.peek().is_some() {
1960 msg += &format!("{} {}, ", res.article(), res.descr());
1962 msg += &format!("and {} {}", res.article(), res.descr());
1968 report_diagnostic(cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, |diag, sp| {
1969 if let Some(sp) = sp {
1970 diag.span_label(sp, "ambiguous link");
1972 diag.note("ambiguous link");
1975 for res in candidates {
1976 suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
1981 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
1983 fn suggest_disambiguator(
1985 diag: &mut Diagnostic,
1988 sp: Option<rustc_span::Span>,
1990 let suggestion = res.disambiguator_suggestion();
1991 let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
1993 if let Some(sp) = sp {
1994 let mut spans = suggestion.as_help_span(path_str, ori_link, sp);
1995 if spans.len() > 1 {
1996 diag.multipart_suggestion(&help, spans, Applicability::MaybeIncorrect);
1998 let (sp, suggestion_text) = spans.pop().unwrap();
1999 diag.span_suggestion_verbose(sp, &help, suggestion_text, Applicability::MaybeIncorrect);
2002 diag.help(&format!("{}: {}", help, suggestion.as_help(path_str)));
2006 /// Report a link from a public item to a private one.
2007 fn privacy_error(cx: &DocContext<'_>, diag_info: &DiagnosticInfo<'_>, path_str: &str) {
2009 let item_name = match diag_info.item.name {
2014 None => "<unknown>",
2017 format!("public documentation for `{}` links to private item `{}`", item_name, path_str);
2019 report_diagnostic(cx.tcx, PRIVATE_INTRA_DOC_LINKS, &msg, diag_info, |diag, sp| {
2020 if let Some(sp) = sp {
2021 diag.span_label(sp, "this item is private");
2024 let note_msg = if cx.render_options.document_private {
2025 "this link resolves only because you passed `--document-private-items`, but will break without"
2027 "this link will resolve properly if you pass `--document-private-items`"
2029 diag.note(note_msg);
2033 /// Resolve a primitive type or value.
2034 fn resolve_primitive(path_str: &str, ns: Namespace) -> Option<Res> {
2038 use PrimitiveType::*;
2039 let prim = match path_str {
2055 "bool" | "true" | "false" => Bool,
2056 "str" | "&str" => Str,
2057 // See #80181 for why these don't have symbols associated.
2062 "pointer" | "*const" | "*mut" => RawPointer,
2063 "reference" | "&" | "&mut" => Reference,
2065 "never" | "!" => Never,
2068 debug!("resolved primitives {:?}", prim);
2069 Some(Res::Primitive(prim))
2072 fn strip_generics_from_path(path_str: &str) -> Result<String, MalformedGenerics> {
2073 let mut stripped_segments = vec![];
2074 let mut path = path_str.chars().peekable();
2075 let mut segment = Vec::new();
2077 while let Some(chr) = path.next() {
2080 if path.next_if_eq(&':').is_some() {
2081 let stripped_segment =
2082 strip_generics_from_path_segment(mem::take(&mut segment))?;
2083 if !stripped_segment.is_empty() {
2084 stripped_segments.push(stripped_segment);
2087 return Err(MalformedGenerics::InvalidPathSeparator);
2095 return Err(MalformedGenerics::TooManyAngleBrackets);
2098 return Err(MalformedGenerics::EmptyAngleBrackets);
2103 while let Some(chr) = path.next_if(|c| *c != '>') {
2110 _ => segment.push(chr),
2112 trace!("raw segment: {:?}", segment);
2115 if !segment.is_empty() {
2116 let stripped_segment = strip_generics_from_path_segment(segment)?;
2117 if !stripped_segment.is_empty() {
2118 stripped_segments.push(stripped_segment);
2122 debug!("path_str: {:?}\nstripped segments: {:?}", path_str, &stripped_segments);
2124 let stripped_path = stripped_segments.join("::");
2126 if !stripped_path.is_empty() { Ok(stripped_path) } else { Err(MalformedGenerics::MissingType) }
2129 fn strip_generics_from_path_segment(segment: Vec<char>) -> Result<String, MalformedGenerics> {
2130 let mut stripped_segment = String::new();
2131 let mut param_depth = 0;
2133 let mut latest_generics_chunk = String::new();
2138 latest_generics_chunk.clear();
2139 } else if c == '>' {
2141 if latest_generics_chunk.contains(" as ") {
2142 // The segment tries to use fully-qualified syntax, which is currently unsupported.
2143 // Give a helpful error message instead of completely ignoring the angle brackets.
2144 return Err(MalformedGenerics::HasFullyQualifiedSyntax);
2147 if param_depth == 0 {
2148 stripped_segment.push(c);
2150 latest_generics_chunk.push(c);
2155 if param_depth == 0 {
2156 Ok(stripped_segment)
2158 // The segment has unbalanced angle brackets, e.g. `Vec<T` or `Vec<T>>`
2159 Err(MalformedGenerics::UnbalancedAngleBrackets)